I am diabetic operated for cataract one year ago now I see some black clouds in vision. What should I do?

Get evaluated. Cataract surgery involves the optics of the eye. The retina is the part of the eye attacked in uncontrolled diabetes, with vascular dilation, edema and bleeding. If you see black clouds you might have hemorrhage, or even a detachment of the retina. You should see your ophthalmologist right away (not an optometrist).
Diabetes, cataract s. Most common cause of black clouds in vision p CS is PVD (posterior vitreous detachment): very common & usually no complications & resolves over time. Diabetes though can affect retina (diabetic retinopathy, proliferative retinopathy) before & after cataract surgery. See your eyeMD: Be sure your vitreous (no blood) & retina are normal; see your eyeMD as soon as possible. eyedoc2020.Blogspot.com.